1. Field of the Invention
A bone fixation system and method suitable, for example, for fracture fixation of the proximal phalanx of the hand or foot, especially of the hyperextension type, are provided. The system is also suitable for fixating fractures of other long bones of the hand, such as the middle phalanx or the metacarpals, and of the metatarsals in the foot. The system is also suitable for fixating fractures in other bones outside of the hand or foot.
2. Description of the Prior Art
Hyperextension fractures of the proximal phalanx are typically problematic, especially in the elderly, because such fractures are very difficult to stabilize. Current techniques and devices can often lead to very significant functional impairment and disability. These hyperextension fractures of the proximal phalanx usually result in less optimal outcomes than fractures of larger bones such as the distal radius.
One of the most common methods for fracture fixation is pinning. In general, a pin has a sharp cutting tip. The pin is driven into bone with the aide of a drill or an equivalent mechanical device. Despite their versatility, pins have limitations especially with fractures that have a significant amount of fragmentation (comminution) of the bone at the fracture site or when the fractured bone is too soft resulting in premature loosening of the pins.
Another common method for fracture fixation of the small bones of the hand utilizes plate fixation. However, use of plates usually results in scaring which frequently limits the proper gliding motion of the surrounding tendons, especially the extensor tendon. A second surgery is usually necessary to remove the plate and release the extensor tendon. This approach often results in a large scar in the most visible part of the hand (not readily received by most female patients). In the presence of significant comminution and osteoporosis, as is often the case scenario in the elderly female population with these fractures, plate fixation of hyperextension fractures of the proximal phalanx is usually not able to hold the alignment of the fracture because the plate has limited mechanical ability to buttress these fractures and loss of reduction is often frequent after plate fixation.
In addition, conventional plating of the long bones of the hand frequently results in malalignment of the involved bone after the plate is applied; the operated finger will tend to abnormally scissor or overlap onto an adjacent finger. Thus, plating requires absolute precision because even a small amount of angular malalignment is not well tolerated.
Yet another fixation method utilizes a flexible nail/pin mated to a locking sleeve. This method offers some advantages over plating and pinning of the long bones of the hand. However, the nail and sleeve configuration is not much different from pins and has limited ability to control hyperextension fractures of the proximal phalanx which frequently results in loss of fracture reduction. In addition, a significant portion of the hardware is prominent outside of the bone, irritating the tendons. Some relief is provided by use of a protective plastic cap. In most cases, a second surgery is needed to remove the nail and the prominent locking sleeve.